Momentum in south Yemen swung again on Thursday as newly reinforced southern forces recaptured parts of Aden city and Abyan province from fighters loyal to President Abd Rabbuh Mansour Hadi.

Battles are now raging around Aden and to its east with Hadi’s forces gathering around the Abyan village of al-Alam, preparing to launch a counterattack and seize back parts of the city it won the day before.

The situation in south Yemen is extremely fluid, with territory constantly exchanged between the UAE-backed Security Belt Forces (SBF) and troops loyal to the Hadi government, which is supported by Saudi Arabia.

Emirati warplanes are targeting pro-government forces in Aden and Zinjibar, sources and local media have reported.

The state-run Saba news agency said the air strikes killed and wounded government forces and civilians.

The government said the UAE must take full responsibility for the "illegal, blatant attack" and demanded Abu Dhabi end its financial and military support for the SBF.

“The Yemeni government reserves the legal right, which is guaranteed by the international law and the United Nations Charter, to do the required procedures to stop this attack and dangerous escalation,” the government said in a statement.

On Wednesday, Hadi’s soldiers overran the SBF, sweeping the southerners from territory they had gained in Abyan and Lahj provinces, before claiming they had regained control of Aden.

South Yemen: Timeline of a civil war within a civil war

1 August: A missile attack claimed by the Houthis kills dozens of Security Belt Forces (SBF) officers at a military parade near Aden, including a leading SBF commander, Brigadier General Munir “Abu al-Yamama” al-Yafee. The Houthis claim responsibility, but the UAE-backed Southern Transitional Council (STC), the SBF's political wing, blame the attack on al-Islah, which it said had infiltrated President Abd Rabbuh Mansour Hadi's government and military, including the presidential guard stationed at al-Maashiq presidential palace in Aden.

7 August: Gunshots are reportedly fired at Yafee's funeral, which was held near Aden's presidential palace. Fighting breaks out between SBF fighters and presidential guards at the palace entrance. The STC claims 11 of its members were killed in the exchange of fire. Later that evening, STC Vice Chairman Hani bin Breik calls for supporters to march on the presidential palace to overthrow Hadi's government.

8 August: At least 12 people are killed in renewed clashes between the SBF and pro-Hadi forces in Aden.

10 August: The STC captures Aden after a fierce battle with loyalist forces. At least eight civilians are killed in the fighting. The Saudi-backed government accuses the STC of staging a coup in the southern port city after its fighters seized all military camps, prompting Riyadh to call for an urgent meeting for the warring parties.

20 August: SBF fighters encircle a pro-government special forces camp in the Zinjibar, the capital of Abyan province. The special forces camp and a nearby military base both fall under the control of the SBF.

22 August: The Shabwani Elite Forces (SEF), a militia loyal to the STC, attacks government forces in the Shabwa province and captures several areas, including its capital city of Ataq.

28 August: Pro-government forces recapture Abyan province and Hadi's information minister announces Aden has been taken back and its presidential palace seized.

29 August: STC forces regain parts of Aden city and Abyan province. The UAE claims responsibility for airstrikes against what it calls "terrorist organisations", and Hadi calls on Saudi Arabia rein in the separatists, saying his forces have withdrawn from the city to prevent further destruction.

The Yemeni government lost Aden earlier this month, and had been on the back foot until the SBF came across fierce resistance from Saudi-backed forces in eastern Shabwa province.

No force appears dominant, and with the constant advances and withdrawals it is near impossible to judge who controls Aden and Abyan. However, it is clear that both sides are receiving military reinforcements and there may be fiercer battles in the coming hours.

Mahmoud, a resident in Aden who wished to be identified only by his first name, described to Middle East Eye a confusing and dangerous situation in the city.

“We are trapped in our houses and we hear battles ongoing in several areas in Aden. Yesterday night, we heard air strikes, but we do not know who they were supporting,” he said.

“You can find pro-Hadi fighters and the SBF in the same street, but no-face-to-face clashes - we hope this will not happen in the coming hours.”

Mahmoud said both sides are using weaponry supplied by the Saudi-led coalition fighting the Houthi movement in Yemen’s north, an alliance that both SBF patron the UAE and Hadi-backer Riyadh play an important role in.

“Both sides use the Emirati armoured vehicles and the coalition’s weapons and ammunition, so there is balance in forces which will prolong the clashes,” he said.

According to Mahmoud, military reinforcements were sent to the SBF from Lahj and al-Dhale, areas that the SBF’s political wing the Southern Transitional Council (STC) controls, and this allowed the southerners to advance.

Like many civilians in Aden and Abyan, Mahmoud said he wants peace and that he does not care who controls what.

“I wish the Saudi-led coalition would withdraw the weapons it gave to the warring sides so the fighting would stop,” he said.

STC claims control of Aden

Hani bin Braik, the STC’s deputy chairman, said on Twitter that his forces are abandoning the northern fronts along which they had been fighting the Houthis in order to defend their positions in the south.

He labelled the pro-government forces “Muslim Brotherhood terrorism”, a reference to the number of fighters belonging to al-Islah, the Brotherhood’s Yemeni branch.

“We stayed fighting the Houthis honestly for more than four years, and the terrorist forces stored up the coalition’s support to prepare for invading the south,” bin Braik said.

Salem, an SBF fighter in Aden, sounded upbeat in a call to MEE, during which sounds of clashes could be heard in the background.

'I wish the Saudi-led coalition would withdraw the weapons it gave to the warring sides so the fighting would stop'

- Mahmoud, Aden resident

“Military reinforcements reached to Aden and Abyan not only from the south, but also a whole brigade left the battles against the Houthis on the western coast and joined us this morning,” he said.

“That was a main reason we have regained control of Aden and the Jaar district in Abyan, and we are pursuing the northern militias in Aden and advancing towards Zinjibar.”

Salem confirmed that his forces will now not participate in any battle against the Houthis in the north, and said they will do their best to secure Aden and the south from “invaders”.

“I call on all southern fighters in the north and especially in the western coast to return and defend Aden from militias, as Aden now needs southern people to achieve independence and liberate the south from invaders.”

The STC seeks the independence of Yemen’s south, which was a separate state from 1967 to 1990.

Sobaihi masses troops

In Abyan’s al-Alam, the entrance to Aden, Hadi’s forces are massing under the leadership of Brigadier Abdullah al-Sobaihi, commander of Brigade 39. Reinforcements are arriving from Shabwa and Abyan provinces.

A pro-Hadi Aden resident, who wished to remain anonymous, told MEE he was confident in Sobaihi’s leadership.

'Sobaihi is a seasoned military leader and he has participated in many battles so we trust him to lead Aden battle'

- Hadi supporter

“Sobaihi is a seasoned military leader and he has participated in many battles so we trust him to lead the Aden battle,” he said.

The resident acknowledged that the SBF had seized some areas in Aden this morning, but said Hadi’s forces’ withdrawal was tactical and expressed confidence they will advance from Abyan to take Aden.

However, he said UAE warplanes were attacking Sobaihi’s fighters.

“The air strikes targeted Sobaihi’s forces this afternoon, killing and wounding some. This is a clear message to the world that the UAE supports the militia against the government,” he said.